The present invention relates to a stator of a rotating electric machine and particularly to a stator suitable for a synchronous electric machine.
In a stator of a rotating electric machine such as a synchronous electric machine, in generally, as shown in FIG. 21, the stator is formed by using a stator iron core 2 having a tooth portion 3a which is arranged in a circumferential direction and a slot 3 between the tooth portions 3a. On the slot 3 an insulating slot liner 3b (hereinafter called xe2x80x9ca slot linerxe2x80x9d) is mounted, and in an interior portion thereof a predetermined wound transformed coil 4 is inserted and similarly to a predetermined wedge 3c is mounted.
Further, FIG. 22 shows a cross-section of the inner portion of the slot 3. On the other hand, a stator coil 4 has a shape configuration shown in FIG. 23 and the stator coil 4 is formed in a manner in which a winding frame not shown in figure which has a substantially similar shape as the shape of the stator coil 4 is formed in advance and to this winding frame the coil 4 is wound in a predetermined turn number. And the above stated stator coil 4 is inserted into the interior portion 3a of the slot 3 from an opening portion of the slot 3 using a mutual working technique or a machine apparatus.
However, the prior art does not take fully into consideration the shortening of the length of a coil end portion, and accordingly, there is a problem about the small size of the rotating electric machine.
The problem of the lengthening about the length of the coil end portion in the prior art will be explained as follows.
The stator coil 4 has a predetermined number of slot straddling (hereinafter it is called as xe2x80x9cstraddlingxe2x80x9d) which is determined by a number of poles of the stator, and the length of the coil end is put under the control of the size of the straddling.
In general, when the number of the poles is large, since the straddling of the coil is small, the length of the coil end becomes short in comparison with the small number of the poles. Further, in accordance with the device of the shape configuration of the coil end portion of a winding frame which is used during the winding working of the coil, then the length of the coil end can be formed short to some degree.
However, when the length of the coil end is short widely, to the coil end of the coil which has been inserted, the coil end which is to be inserted interferes, and then it is impossible to carry out the insertion of the coil.
Heretofore, the length of the coil has been made no more than the length which does not disturb the coil insertion during the coil winding time. After all of the coil insertion has been finished, using an outside force the coil end is transformed compulsively to an axial direction and a radial direction and is shortened.
According to the above, since the coil end is transformed using a large mechanical force, the slot liner and a coil covering enamel insulation are injured. It is thus possible to carry out the voltage withstanding failure of the stator and further even the compulsive transformation performance, but there is a limitation about the shortening of the coil length. Accordingly, the prior art approach does not correspond to the present desire of users.
An object of the present invention takes into consideration the problem with the above stated prior art technique and provides a stator of a small size rotating electric machine in which a length of a coil end portion of a stator coil can be shortened.
According to the present invention, the coil is not formed by the winding which is as shown in the prior art, within four sides which constitute a closed circuit of the coil, only a radial direction component portion of one side is separated, and the leaving three sides are formed with U-shape configuration and after they are inserted into the slots, between anti-U-shape side opening ends is connected by the radial direction component portion of the one side and then the coil is formed as the closed circuit and is with a predetermined winding turn number.
Further, to attain the full and good connection, when the anti-U-shape side opening end and the radial direction component portion, in other words the thin plate rod chip are overlapped and they are connected, a plate thickness of the overlapped portion of the both are reduced by half respectively in advance, the plate thickness in which the both are overlapped is formed to correspond the plate thickness of the coil.
For this reason, a face in which the plate thickness is reduced half, in the U-shape coil, one end of the anti-U-shape side, for example, in a left side, is formed a face which directs for an inner diameter of the stator and a right side end is formed to a face which directs for an outer diameter of the stator. On the other hand, in the thin rod shape chip, the face in which the plate thickness is reduced by half is formed a face which is an anti-face against the coil.
The coil is formed with the above stated construction, when they are overlapped, according to the linear portion two sides of the U-shape coil, the thin plate rod shape chip is functioned to be sandwiched, and a full and solid connection can be realized.
When the coil is constituted with the above construction, since a straddling width of the coil is determined by the adjacent slot widths, an axial direction length of the U-shape component portion which projects from a stator iron core becomes to correspond the adjacent slot widths.
On the other hand, in the anti-U-shape side of the coil since an axial direction length of the component portion which projects from the stator iron core is connected by the thin plate rod shape chip, in the axial direction it occupies only the corresponded width of the above stated thin plate connection chip, accordingly the coil in which the length of the coil end portion can be shortened surely can be provided.